No one has come closer to experiencing the enduring solitude and high-risk travel that would accompany a mission to Mars than the three astronauts who flew to the International Space Station on November 23, 2002.

Just nine weeks later, the space shuttle Columbia exploded.
That led controllers to extend the Expedition 6 mission, as
the trio’s endeavor was known, from four to five and a half
months — about the time needed for a trip to Mars. On the
journey back from the space station, a spacecraft malfunction
caused a high-speed reentry to Earth’s atmosphere, approaching speeds that would be reached when nearing Mars. The
Expedition 6 capsule bumped and rolled to a stop about 475
kilometers off course, in a remote part of West Asia. The crew
was rescued five hours later.

As they waited, the astronauts pulled themselves out of theirbattered craft, set up two radio systems and performed othersurvival procedures — all with great difficulty. The men’s bod-ies had become accustomed to the lack of gravity in space, sotheir limbs felt like dead weights. Each head movement causeda wave of dizziness. Two crew members with experiencereadjusting to Earth conditions during previous missions tothe space station staggered about slowly. Rookie space travelerDon Pettit crawled back and forth between the capsule and thecrew’s new base camp.

It wasn’t easy, but Expedition 6 demonstrated that a space
station crew could perform critical procedures in a situation
similar to a Mars trip and landing, Pettit wrote in 2010 in the
Journal of Cosmology.

He acknowledged, however, that a longer Mars voyage
would bring novel emotional and social challenges.

Much is known about the psychology of participating
in space missions that circle Earth at relatively close range
or venture to the moon. Scientists are in the early stages,